This invention provides a matrix comprising molecules of a suitable polymer which provides solely on the surface of the matrix sufficient uncharged substituted amide groups to render the surface hydrophilic. The invention also provides an article of manufacture comprising the matrix.Another aspect of the invention provides a method of producing a matrix having a hydrophilic surface which comprises treating molecules of a suitable polymer so as to provide solely on the surface of the matrix sufficient uncharged, hydrophilic substituted amide groups to render the surface hydrophilic.Another embodiment of the invention concerns improved methods of filtration, ultrafiltration, microfiltration, reverse osmosis, dialysis, prevaporation, sieving, affinity chromatography, affinity purification, affinity separation, or affinity adsorption which comprises using the article of manufacture.